Adolescent alcohol and cannabis use and early adulthood educational attainment in the 1986 Northern Finland birth cohort study.

BACKGROUND: Heavy alcohol and cannabis use during adolescence have been previously described as risk factors not only for morbidity in adulthood, but also social problems including adversities in educational attainment. Attempts to consider overlapping risk factors and confounders for these associations are needed. METHODS: Using weighted multivariable models, we examined prospective associations between age at first drink (AFD), age at first intoxication (AFI), frequency of alcohol intoxication, as well as self-reported alcohol tolerance (i.e., number of drinks needed for the subjective experience of intoxication), and lifetime cannabis use at age 15/16 years with subsequent educational attainment obtained from comprehensive registers until age 33 in the Northern Finland Birth Cohort 1986 (6,564 individuals, 49.1% male). Confounding variables including sex, family structure (intact vs. non-intact), maternal and paternal education level, behavioural/emotional problems in school at age 7/8 years, having a history of illicit substance use in adolescence, having any psychiatric diagnosis before age 16, and parental psychiatric diagnoses, were adjusted for. RESULTS: In this large birth cohort study with a 17-year follow-up, younger age at first intoxication, higher frequency of alcohol intoxication, and high self-reported alcohol tolerance at age 15/16 years were associated with poorer educational outcomes by the age of 33 years. These associations were evident regardless of potential confounders, including parental education and childhood behavioural/emotional problems. The association between adolescent cannabis use and educational attainment in adulthood was no longer statistically significant after adjusting for confounders including frequency of alcohol intoxication at age 15/16. CONCLUSIONS: Assessments of age of first alcohol intoxication, high self-reported alcohol tolerance and frequency of intoxication during adolescence should be included when implementing screening strategies aimed at identifying adolescents at risk for subsequent social problems.

Adolescent alcohol and cannabis use as risk factors for head trauma in the Northern Finland Birth Cohort study 1986.

BACKGROUND: The aim of this study was to assess the associations between cannabis use and frequency of alcohol intoxication in adolescence with the risk of traumatic brain injury and craniofacial fractures in early adulthood. Hypothesis was that using alcohol and cannabis in adolescence could increase the risk for head traumas. METHODS: Data from the Northern Finland Birth Cohort 1986 (n = 9432 individuals) were used to investigate the prospective association between the self-reported frequency of alcohol intoxication (n = 6472) and cannabis use (n = 6586) in mid-adolescence and register-based, head trauma diagnoses by ages 32-33 years. To test the robustness of these associations, the statistical models were adjusted for a range of other confounders such as illicit drug use, previous head trauma and self-reported mental health problems. RESULTS: In multivariate analyses, cannabis use was statistically significantly associated with a greater risk of traumatic brain injury among females [hazard ratio (HR) 1.9, 95% confidence interval (CI) 1.1-3.2, P = 0.024). Frequent alcohol intoxication was a statistically significant independent risk factor for both traumatic brain injury (HR 2.6, 95% CI 1.7-3.9, P < 0.001) and craniofacial fractures (HR 2.7, 95% CI 1.6-4.8, P < 0.001) among males. CONCLUSIONS: Cannabis use in adolescence appears to associate independently with elevated risk for traumatic brain injury among females, and frequent alcohol intoxication in adolescence seems to associate with elevated risk of both traumatic brain injury and craniofacial fractures among males.

Attention deficit hyperactivity and oppositional defiant disorder symptoms in adolescence and risk of substance use disorders-A general population-based birth cohort study.

BACKGROUND: Externalizing symptoms are associated with risk of future substance use disorder (SUD). Few longitudinal studies exist using general population-based samples which assess the spectrum of attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) symptoms. AIMS/OBJECTIVES: We aimed to study the associations between adolescent ADHD symptoms and subsequent SUD and additionally examine whether the risk of SUD is influenced by comorbid oppositional defiant disorder (ODD) symptoms. METHODS: The Northern Finland Birth Cohort 1986 was linked to nationwide health care register data for incident SUD diagnoses until age 33 years (n = 6278, 49.5% male). ADHD/ODD-case status at age 16 years was defined using parent-rated ADHD indicated by Strengths and Weaknesses of ADHD symptoms and Normal Behaviors (SWAN) questionnaire with 95% percentile cut-off. To assess the impact of ODD comorbidity on SUD risk, participants were categorized into four groups based on their ADHD/ODD case status. Cox-regression analysis with hazard ratios (HRs) and 95% confidence intervals (CIs) were used to study associations between adolescent ADHD/ODD case statuses and subsequent SUD. RESULTS: In all, 552 participants (8.8%) presented with ADHD case status at the age of 16 years, and 154/6278 (2.5%) were diagnosed with SUD during the follow-up. ADHD case status was associated with SUD during the follow-up (HR = 3.84, 95% CI 2.69-5.50). After adjustments for sex, family structure, and parental psychiatric disorder and early substance use the association with ADHD case status and SUD remained statistically significant (HR = 2.60, 95% CI 1.70-3.98). The risk of SUD remained elevated in individuals with ADHD case status irrespective of ODD symptoms. CONCLUSIONS: ADHD in adolescence was associated with incident SUD in those with and without symptoms of ODD. The association of ADHD and SUD persisted even after adjustment for a wide range of potential confounds. This emphasizes the need to identify preventative strategies for adolescents with ADHD so as to improve health outcomes.

Associations of Adolescent Alcohol Use and Self-Reported Alcohol Tolerance With Risk of Self-Harm and Suicide in Early Adulthood: A Birth-Cohort Study.

OBJECTIVE: We aimed to assess the predictive associations of age at first drink (AFD), age at first intoxication (AFI), frequency of intoxication, and self-reported alcohol tolerance at ages 15-16 with self-harm requiring medical attention or suicide death by age 33. METHOD: In an ongoing follow-up study, the Northern Finland Birth Cohort 1986, a total of 7,735 individuals were included at ages 15-16. Information on alcohol and other substance use was assessed via questionnaires. Information on self-harm or suicide was collected from national registers until the participants were 33 years of age. Baseline psychiatric symptomatology measured with the Youth Self-Report questionnaire and sociodemographic background variables were controlled for in multivariable analyses using Cox regression analyses. RESULTS: Male gender and psychiatric symptoms at ages 15-16 were consistently associated with greater risk of self-harm and suicide death. When baseline psychiatric symptomatology and other background variables were adjusted for, younger AFI (hazard ratio [HR] = 2.28, 95% CI [1.16, 4.47]) and high inherent alcohol tolerance (HR = 3.76, 95% CI [1.55, 9.08]) were associated with self-harm. Furthermore, frequent alcohol intoxication (HR = 5.39, 95% CI [1.44, 20.23]) and high inherent alcohol tolerance (HR = 6.20, 95% CI [1.18, 32.45]) were associated with suicide death by age 33. CONCLUSIONS: High alcohol tolerance, age at onset of intoxication, and frequency of alcohol intoxication in adolescence appear to be significant predictors of self-harm and suicide in early adulthood. Self-reported alcohol tolerance in adolescence is a novel empirical approach to assess adolescent alcohol use associating with subsequent harms.

Association of ADHD symptoms in adolescence and mortality in Northern Finland Birth Cohort 1986.

BACKGROUND: Diagnosis of attention deficit hyperactive disorder (ADHD) has been associated with increased risk of mortality in large register samples. However, there is less known about the association between symptoms of ADHD in adolescents and risk of mortality in general population samples. METHODS: The Northern Finland Birth Cohort 1986 (n = 9432 at recruitment in early pregnancy) linked to nationwide register data for deaths was utilized to study the association between parent-rated ADHD symptoms assessed using Strengths and Weaknesses of ADHD symptoms and Normal Behaviors (SWAN) questionnaire and mortality until age 33 years. Cox-regression analysis with hazard ratios (HRs) and 95% confidence intervals (CIs) was used to study the association between SWAN inattentive, hyperactive, and combined symptom scores and risk of death. RESULTS: Sixty-three (0.9%) of the 6685 participants died during the follow-up. Higher SWAN inattentive (crude HR = 2.30, 95% CI 1.46-3.63), SWAN hyperactive (crude HR = 2.43, 95% CI 1.29-4.56), and SWAN combined (crude HR = 2.69, 95% CI 1.57-4.61) scores were associated with increased risk of death. After adjustments for sex, family structure, and lifetime parental psychiatric disorder, these associations persisted. Further adjustment for frequent alcohol intoxication, cannabis, and other substance use in adolescence attenuated these to below statistical significance. CONCLUSIONS: These results extend previous findings on the risk of mortality in adolescents who have symptoms of ADHD. Further research with larger samples are needed to determine whether the association between ADHD symptoms and mortality is independent of adolescent substance use.

Employment trajectories until midlife in schizophrenia and other psychoses: the Northern Finland Birth Cohort 1966.

PURPOSE: Psychoses are associated with poor labour market attachment, but few studies have compared schizophrenia (SZ) and other psychoses (OP). Moreover, studies on long-term employment trajectories over individuals' working life courses are lacking. We compared 30 year employment trajectory patterns in a general population sample among individuals with SZ, OP, and those with no psychosis (NP). METHODS: Utilising the Northern Finland Birth Cohort 1966, we collected survey data on employment from ages 16 to 45 and detected individuals with register-based history of SZ (n = 62), OP (n = 87), or NP (n = 6464) until age 46. Through gender-specific latent class analyses on annual employment roles, we identified traditional, highly educated, self-employed, delayed and floundering employment trajectories with distinct socioeconomic characteristics. We addressed attrition by conducting weighted analyses. RESULTS: Floundering trajectories were common among individuals with SZ (79% of men, 73% of women) and OP (52% of men, 51% of women). In NP, a traditional employee trajectory was most common in men (31%), and a highly educated trajectory in women (28%). A history of psychosis was associated with heightened odds ratios (ORs; 95% confidence intervals (CIs)) for floundering trajectories in both men (SZ: 32.9 (13.3-81.4); OP: 7.4 (4.0-13.9)) and women (SZ: 9.9 (4.6-21.5); OP: 3.9 (2.1-7.1)) compared to NP. Weighted analyses produced similar results. CONCLUSION: Most individuals with SZ or OP have floundering employee trajectories reflecting an elevated risk of unemployment and part-time work until midlife. These results indicate the importance of improving labour market attachment during the early phases of psychoses.

Social leisure time activities as a mediating link between self-reported psychological symptoms in adolescence and psychiatric morbidity by young adulthood: the Northern Finland 1986 Birth Cohort study.

Research indicates that adolescent psychological symptoms are associated with subsequent mental health disorders. Studies also show the association of leisure activity with improved current and future mental health. However, research is limited on whether social leisure time activity is a mediating link in the association between psychological symptoms and later psychiatric morbidity. We examined whether adolescence-related social leisure time activity, per se, is a mediating link in the association between adolescent psychological symptoms and later psychiatric morbidity. The study population was based on the Northern Finland Birth Cohort 1986 Study (NFBC 1986; n = 6709; 3227 males). Psychological symptoms at age 15-16 years were measured with the Youth Self Report (YSR) questionnaire. Study participants' psychiatric morbidity by the age of 33 years was assessed using the diagnoses from the nationwide health care registers. Our results showed an association between psychological symptoms and leisure time activities that varied depending on the level of social activity. Leisure time activity was found to be a mediating link between psychological symptoms in adolescence and psychiatric disorders in early adulthood. Adolescence-related leisure time activities, which differed with regard to social interactions, appeared to serve as a mediating link between adolescent psychological symptoms and later onset of psychiatric disorders. Socially active leisure time during adolescence is related to better long-term mental health, while socially inactive leisure time associates with the likelihood of later psychiatric morbidity. To prevent psychiatric disorders, enhancing such leisure time activities in society is highly recommended.

The relationships between use of alcohol, tobacco and coffee in adolescence and mood disorders in adulthood.

INTRODUCTION: Alcohol, tobacco and coffee are commonly used substances and use in adolescence has previously been linked to mood disorders. However, few large prospective studies have investigated adolescent use in relation to mental health outcomes in adulthood. The main aim of this study was to examine the prospective associations between alcohol use, cigarette smoking and coffee consumption at age 16 and subsequent mood disorders up to 33 years of age. METHODS: Data from The Northern Finland Birth Cohort 1986 Study were used and a total of 7660 participants (49.9% male) were included. Associations between alcohol use, cigarette smoking and coffee consumption at age 16 and later diagnoses of major depression and bipolar disorder were examined using multinomial logistic regression analyses. RESULTS: Mean number of cigarettes/day (OR, 1.23 [95% CI 1.01-1.50]) and mean volume of alcohol consumption (OR, 1.22 [95% CI 1.01-1.47]), but not frequency of excessive drinking, in adolescence were associated with increased risk for subsequent bipolar disorder after adjustment for sex, parental psychiatric disorders, family structure, illicit substance use, and emotional and behavioral problems at age 16. An association between cigarette smoking and major depression attenuated to statistically non-significant when adjusted for emotional and behavioral problems. No associations were observed between adolescent coffee consumption and subsequent mood disorders. CONCLUSIONS: This is the first study to report an association of adolescent cigarette smoking and subsequent bipolar disorder diagnosis providing grounds for further research and pointing to a place for preventive measures among adolescents.

Alcohol use in adolescence as a risk factor for overdose in the 1986 Northern Finland Birth Cohort Study.

BACKGROUND: Overdoses and poisonings are among the most common causes of death in young adults. Adolescent problem drinking has been associated with psychiatric morbidity in young adulthood as well as with elevated risk for suicide attempts. There is limited knowledge on adolescent alcohol use as a risk factor for alcohol and/or drug overdoses in later life. METHODS: Here, data from The Northern Finland Birth Cohort 1986 study with a follow-up from adolescence to early adulthood were used to assess the associations between adolescent alcohol use and subsequent alcohol or drug overdose. Three predictors were used: age of first intoxication, self-reported alcohol tolerance and frequency of alcohol intoxication in adolescence. ICD-10-coded overdose diagnoses were obtained from nationwide registers. Use of illicit drugs or misuse of medication, Youth Self Report total score, family structure and mother's education in adolescence were used as covariates. RESULTS: In multivariate analyses, early age of first alcohol intoxication [hazard ratios (HR) 4.5, 95% confidence intervals (CI) 2.2-9.2, P < 0.001], high alcohol tolerance (HR 3.1, 95% CI 1.6-6.0, P = 0.001) and frequent alcohol intoxication (HR 1.9, 95% CI 1.0-3.4, P = 0.035) all associated with the risk of overdoses. Early age of first intoxication (HR 5.2, 95% CI 1.9-14.7, P = 0.002) and high alcohol tolerance (HR 4.4, 95% CI 1.7-11.5, P = 0.002) also associated with intentional overdoses. CONCLUSIONS: Alcohol use in adolescence associated prospectively with increased risk of overdose in later life. Early age of first intoxication, high alcohol tolerance and frequent alcohol intoxication are all predictors of overdoses.

Substance use confounds associations between peer victimization and aggression in adolescence with mental disorders in adulthood: A prospective birth cohort study.

INTRODUCTION: Peer victimization and aggression in adolescence are associated with later mental health morbidity. However, studies examining this association have not controlled for adolescent substance use. We aimed to study the associations between peer victimization, peer aggression, and mental disorders in adulthood, adjusting for substance use in adolescence. METHODS: Participants were from the prospective Northern Finland Birth Cohort 1986. Data were available for 6682 individuals (70.8% of the original sample). Peer victimization and peer aggression were assessed with items from the Achenbach Youth Self Report at ages 15-16 years. Outcomes were nonorganic psychosis, anxiety disorder, mood disorder, substance use disorder, and any mental disorder (a none-vs-any indicator) at age 33 years collected from nationwide health care, insurance, and pension registers. Family structure, alcohol intoxication frequency, daily smoking, illicit drug use, and baseline psychopathology using Youth Self-Report total score, and parental mental disorders were considered as confounding factors. RESULTS: In multivariable analyses, the association between peer victimization and psychosis (Hazard ratio [HR]: 2.9, 95% confidence interval [CI]: 1.2-6.9, p = .020) and mood disorder (HR: 1.7, 95% CI: 1.2-2.4, p = .012) in females remained significant after adjusting for confounders. Other associations between female and male peer victimization or aggression and the studied outcomes attenuated after adjustments. CONCLUSIONS: Some associations between peer victimization and aggression and later mental health morbidity are explained by adolescent substance use. For females, substance use does not account for the increased risk of psychosis and mood disorder in those who experience peer victimization.

Trajectories of adolescent psychotic-like experiences and early cannabis exposure: Results from a Finnish Birth Cohort Study.

BACKGROUND: Longitudinal studies examining the effect of cannabis exposure (CE) on the prognosis of adolescents with psychotic-like experiences (PLEs) are scarce. We examined trajectories of mental health in adolescents with PLEs and cannabis exposure. METHODS: The Northern Finland Birth Cohort 1986 (n = 6552) with linkage to nationwide register data was used. Information on lifetime cannabis exposure was collected when participants were aged 15/16. Register-based outcome data on diagnoses made in clinical practice were obtained until age 33. Logistic regression was used to study the association of PLE/CE patterns and subsequent psychiatric disorders. The group with neither PLEs nor CE was utilized as the reference group. Parental psychiatric disorders, family structure, sex, frequent alcohol intoxications, daily smoking and illicit substance use other than cannabis were adjusted for. RESULTS: In all, 6552 subjects (49.2 % males) were included in analysis. PLEs with cannabis exposure were associated with any psychiatric disorder (OR = 2.59; 95 % CI 1.82-3.68), psychotic disorders (OR = 3.86; 95 % CI 1.83-8.11), mood disorders (OR 4.07; 95 % CI 2.74-6.04), depressive disorders (OR = 4.35; 95 % CI 2.93-6.48), anxiety disorders (OR = 2.06; 95 % CI 1.34-3.17) and substance use disorders (OR = 2.26; 95 % CI 1.13-4.50) compared to reference group. Effect sizes were greater for group with both PLEs and cannabis use than for group with PLEs only. CONCLUSIONS: Early-onset cannabis use is an adverse prognostic marker for adolescents with PLEs after extensive confounder control including other substance use.

The association between the social environment of childhood and adolescence and depression in young adulthood - A prospective cohort study.

BACKGROUND: Good social relationships with parents and peers protect children and adolescents from developing mental disorders in adulthood while several negative experiences increase the risk of depression in later life. METHODS: We used population-based cohort data from the Northern Finland Birth Cohort (NFBC) 1986. Participants (n = 6147), their teachers and parents reported factors associated with the social environment of children and adolescents. Diagnoses of depression of cohort members were derived from Finnish nationwide registers. We conducted regression analyses to assess which factors of the social environment of childhood and adolescence were associated with depression in young adulthood. RESULTS: Bullying victimization in adolescence was the strongest predictor of depression in young adulthood among girls (OR 2.23: 95% CI 1.47-3.39) and boys (OR 2.44: 95% CI 1.49-4.00). Loneliness and bullying behavior in childhood were associated with depression in boys only. Loneliness in adolescence (OR 1.63: 95% CI 1.30-2.04) was associated with depression among both genders. Spending with the family seemed to protect against the negative impact of bullying and loneliness. LIMITATIONS: We used single-item study questions to measure social relationships. These questions do not necessarily describe the phenomena as accurately as the measures validated for them. CONCLUSION: Problems in social relationships with peers in childhood and adolescence are associated with depression in young adulthood. Time spent with the family is emphasized in situations in which adolescents have problems in peer-relationships.

Is early exposure to cannabis associated with bipolar disorder? Results from a Finnish birth cohort study.

BACKGROUND AND AIMS: There are few longitudinal studies assessing the association of cannabis use and subsequent onset of bipolar disorder. We aimed to measure the association between early cannabis exposure and subsequent bipolar disorder. DESIGN, SETTING AND PARTICIPANTS: Observational study linking a sample from the northern Finland birth cohort 1986 (n = 6325) to nation-wide register data to examine the association of life-time cannabis exposure at age 15/16 years and subsequent bipolar disorder until age 33 (until the end of 2018); 6325 individuals (48.8% males) were included in the analysis. MEASUREMENTS: Cannabis exposure was measured via self-report. Bipolar disorder was measured via bipolar disorder-related diagnostic codes (ICD-10: F30.xx, F31.xx) collected from the Care Register for Health Care 2001-18, the Register of Primary Health Care Visits 2011-18, the medication reimbursement register of the Social Insurance Institution of Finland 2001-05 and the disability pensions of the Finnish Center for Pensions 2001-16. Potential confounders included demographic characteristics, parental psychiatric disorders, emotional and behavioral problems and other substance use. FINDINGS: Three hundred and fifty-two adolescents (5.6%) reported any cannabis use until the age of 15-16 years. Of the whole sample, 66 (1.0%) were diagnosed with bipolar disorder. Adolescent cannabis use was associated with bipolar disorder [hazard ratio (HR) = 3.46; 95% confidence interval (CI) = 1.81-6.61]. This association remained statistically significant after adjusting for sex, family structure and parental psychiatric disorders (HR = 3.00; 95% CI = 1.47-6.13) and after further adjusting for adolescent emotional and behavioral problems (HR = 2.34; 95% CI = 1.11-4.94). Further adjustments for frequent alcohol intoxications, daily smoking and lifetime illicit drug use attenuated the associations to statistically non-significant. CONCLUSIONS: In Finland, the positive association between early cannabis exposure and subsequent development of bipolar disorder appears to be confounded by other substance use.

Parental smoking and young adult offspring psychosis, depression and anxiety disorders and substance use disorder.

BACKGROUND: To study the associations between maternal smoking during pregnancy and paternal smoking before pregnancy and adult offspring psychiatric disorders. METHODS: Prospective general population cohort study in Northern Finland, with people from the Northern Finland Birth Cohort 1986: 7259 subjects (77% of the original sample). Data on parental smoking were collected from parents during pregnancy using questionnaires. Outcomes were offspring's register-based diagnoses: any psychiatric disorder, any non-organic psychosis, mood disorder, anxiety disorder and substance use disorder (SUD) until the age of 29-30 years. Maternal smoking during pregnancy and paternal smoking before pregnancy were pooled to three-class variables: (i) none; (ii) 1-9 and (iii) ≥10 cigarettes/day. Information regarding both parents' alcohol use during pregnancy and at offspring age 15-16 years, maternal education level, family structure, parental psychiatric diagnoses and offspring gender, smoking, intoxication frequency and illicit substance use at the age of 15-16 years were investigated as covariates. RESULTS: In the multivariable analyses, maternal smoking during pregnancy did not associate with the studied outcomes after adjusting for offspring smoking and other substance use at offspring age 15-16 years and parental psychiatric disorders. However, paternal smoking ≥10 cigarettes/day before pregnancy [hazard ratio (HR) = 5.5, 95% confidence interval (CI) 2.7-11.2, P < 0.001] and paternal psychiatric disorders (HR = 1.7, 95% CI 1.1-2.8, P = 0.028) associated with offspring SUD after adjustments. CONCLUSIONS: Information across the offspring life course is essential in exploring the association between parental smoking and offspring psychiatric disorders. Paternal smoking before pregnancy and paternal psychiatric disorders may act as modifiers in elevating the risk of substance-use-related problems among offspring.

Does cannabis use in adolescence predict self-harm or suicide? Results from a Finnish Birth Cohort Study.

OBJECTIVE: Longitudinal studies examining the association between adolescent cannabis use and self-harm are rare, heterogeneous and mixed in their conclusions. We study this association utilizing a large general population-based sample with prospective data. METHODS: The Northern Finland Birth Cohort 1986 (n = 6582) with linkage to nationwide register data was used to study the association of self-reported cannabis use at age 15-16 years and self-harm and suicide death until age 33 (until year 2018), based on register information. Cox regression analysis with Hazard Ratios (HR) and 95% confidence intervals (CI) was used. Psychiatric disorders, parental psychiatric disorders and other substance use were considered as confounders. RESULTS: In all, 6582 (49.2% male) were included in the analysis, and 377 adolescents (5.7%) reported any cannabis use until the age of 15-16 years. Based on register information, 79 (55.7% male) had visited in health care services due to self-harm, and 22 (90.1% male) had died by suicide. In crude analyses, adolescent cannabis use was associated with self-harm (HR = 3.93; 95% CI 2.24-6.90). The association between cannabis use and self-harm remained statistically significant after adjusting for sex, psychiatric disorders at baseline, frequent alcohol intoxications, other illicit drug use, and parental psychiatric disorders (HR 2.06; 95% CI 1.07-3.95). In contrast, the association of cannabis use with suicide did not reach statistical significance even in crude analysis (HR 2.60; 95% CI 0.77-8.78). CONCLUSION: Cannabis use in adolescence may increase risk of self-harm independent of adolescent psychopathology and other substance use.

Associations between Adolescents' Social Leisure Activities and the Onset of Mental Disorders in Young Adulthood.

The association of leisure time activities with specific mental disorders has mainly remained unclear because of lack of such research. This study analyzed the association of different levels of social leisure time activity during adolescence (ages 15-16 years) with the incidence of mental disorders during adolescence and young adulthood between the ages of 16-33 years. The study population consisted of 6838 (females 51.5%) participants from the longitudinal follow-up study, the Northern Finland Birth Cohort 1986, covering 72% of the total 1986 birth cohort. Psychiatric morbidity of the participants was followed through nationwide health registers until the end of the year 2018 when the participants were 33 years old. High social leisure time activity in adolescence associated with lower incidence of psychiatric disorders in general, and specifically, with affective, anxiety, and substance use disorders. Low social leisure time activity was related to increased incidence of any psychiatric disorder in general, and particularly to anxiety and behavioral disorders. In terms of prevention of mental disorders, these study findings encourage families, schools and other communities to continue to enhance and develop community-based social leisure time activities for children and adolescents.

Age of first alcohol intoxication and psychiatric disorders in young adulthood - A prospective birth cohort study.

OBJECTIVE: Early onset of alcohol use is associated with an increased risk of substance use disorders (SUD), but few studies have examined associations with other psychiatric disorders. Our aim was to study the association between the age of first alcohol intoxication (AFI) and the risk of psychiatric disorders in a Finnish general population sample. METHODS: We utilized a prospective, general population-based study, the Northern Finland Birth Cohort 1986. In all, 6,290 15-16-year old adolescents answered questions on AFI and were followed up until the age of 33 years for psychiatric disorders (any psychiatric disorder, psychosis, SUD, mood disorders and anxiety disorders) by using nationwide register linkage data. Cox-regression analysis with Hazard Ratios (HR, with 95% confidence intervals (CI)) was used to assess the risk of psychiatric disorders associated with AFI. RESULTS: Statistically significant associations were observed between AFI and any psychiatric disorder, psychosis, SUDs, and mood disorders. After adjustments for other substance use, family structure, sex and parental psychiatric disorders, AFIs of 13-14 years and ≤12 years were associated with SUD (HR = 5.30; 95%CI 2.38-11.82 and HR = 6.49; 95%CI 2.51-16.80, respectively), while AFI ≤ 12 years was associated with any psychiatric disorder (HR = 1.59; 95%CI 1.26-2.02) and mood disorders (HR = 1.81; 95%CI 1.22-2.68). After further adjustments for Youth Self Report total scores, AFI ≤ 14 was associated with an increased risk of SUD and AFI ≤ 12 with an increased risk of any psychiatric disorder. CONCLUSIONS: We found significant associations between the early age of first alcohol intoxication, later SUD and any psychiatric disorder in a general population sample. This further supports the need for preventive efforts to postpone the first instances of adolescent alcohol intoxication.

Early-Life Risk Factors for Breast Cancer - Prospective Follow-up in the Northern Finland Birth Cohort 1966.

BACKGROUND: While some risk factors for breast cancer have been confirmed, less is known about the role of early biological and social risk factors for breast cancer in adult life. METHODS: In a prospective follow-up in the Northern Finland Birth Cohort 1966 consisting of 5,308 women, 120 breast cancers were reported via national registers by the end of 2018. Early risk factors were examined with univariate and multivariate analyses using Cox regression analysis. The main results are reported with HRs and their 95% confidence intervals (CI). RESULTS: In the multivariate-adjusted models, women whose mothers lived in urban areas (HR, 1.68; 95% CI, 1.13-2.51) during pregnancy, were low educated (HR, 2.40; 95% CI, 1.30-4.45), and had been diagnosed with breast cancer (HR, 1.97; 95% CI, 1.09-3.58) had a higher risk for breast cancer in adult life. Lower BMI at the age of 14 associated nonsignificantly with the risk of breast cancer (Mann-Whitney U test, P = 0.087). No association between birth size and breast cancer risk in adult life was found. CONCLUSIONS: Early-life residence and socioeconomic conditions may have an impact on developing breast cancer in women in adult life. All breast cancer cases of this study were relatively young, and most of them are assumed to be premenopausal. IMPACT: This study is one of a few prospective birth cohort studies to examine early-life socioeconomic factors and breast cancer risk in adult life. This study is limited due to small number of cases.

Adolescent cannabis use, depression and anxiety disorders in the Northern Finland Birth Cohort 1986.

BACKGROUND: Cannabis use has been associated with increased risk of psychiatric disorders. However, associations between adolescent cannabis use, depression and anxiety disorders are inconsistently reported in longitudinal samples. AIMS: To study associations of adolescent cannabis use with depression and anxiety disorders. METHOD: We used data from the Northern Finland Birth Cohort 1986, linked to nationwide registers, to study the association between adolescent cannabis use and depression and anxiety disorders until 33 years of age (until 2018). RESULTS: We included 6325 participants (48.8% male) in the analyses; 352 (5.6%) participants reported cannabis use until 15-16 years of age. By the end of the follow-up, 583 (9.2%) participants were diagnosed with unipolar depression and 688 (10.9%) were diagnosed with anxiety disorder. Cannabis use in adolescence was associated with an increased risk of depression and anxiety disorders in crude models. After adjusting for parental psychiatric disorder, baseline emotional and behavioural problems, demographic factors and other substance use, using cannabis five or more times was associated with increased risk of anxiety disorders (hazard ratio 2.01, 95% CI 1.15-3.82), and using cannabis once (hazard ratio 1.93, 95% CI 1.30-2.87) or two to four times (hazard ratio 2.02, 95% CI 1.24-3.31) was associated with increased risk of depression. CONCLUSIONS: Cannabis use in adolescence was associated with an increased risk of future depression and anxiety disorders. Further research is needed to clarify if this is a causal association, which could then inform public health messages about the use of cannabis in adolescence.